Clinical Cases

Question 1

Answer 1

Atrial Fibrillation (A-fib)

• No P waves, is irregular, tight QRS
• due to ectopic sites of pacemaker activity within the RA and LA causing the atria to contract whenever it wants

Question 2

Answer 2

Atrial Flutter (A-Flutter)

• classic “saw-tooth” pattern

due to multiple (but not as many as afib) extopic pacemakers sites

Question 3

Answer 3

Supraventricular Tachycardia (SVT)

• fast, regular rhythm with no P waves and tight QRS
• single extopic pacemaker site within the atria OR the SA node that beats extremely fast
• REGULAR rhythm, different from afib which is same but IRREGULAR rhythm

Question 4

Answer 4

Premature Atrial Contractions (PACs)

• premature P wave, followed by a QRS, and then an extended “gap” until the next heart beat.
• SA node fires prematurely before the myocytes have repolarized completely

Question 5

Answer 5

Junctional Rhythms

• normal regular rhythm either without P waves, or with inverted P waves.

Arise from the AV node, inverted P wave is normal bc the AV node how has to depolarize in two directions, superior to the remaining atrea and inferior to the ventricles

Question 6

Answer 6

Ventricular Tachycardia (V-tach)

• a fast, wide, “loppy” regular QRS with no P waves.
• the PkF are exclusively firing or firing over the other pacemaker sites

Question 7

Answer 7

Ventricular Fibrillation (V-Fib)

• A course or fine irregular waveform with no discernible morphology.
• ventricles are quivering from any number of reasons
• medical emergency

Question 8

Answer 8

Torsades de Pointes

• undulating, fast rhythm with wide QRS’s and no discernible P waves
• multiple extopic pacemaker sites within the PkF and ventricles fire almost simultaneously

Question 9

Answer 9

Premature Ventricular Contraction (PVCs)

• solitary, wide, odd QRS with no discernible P wave
• a premature contraction arising solely from the PkF or ventricles

Question 10

Answer 10

1 AV Block

• PR interval that exceeds .2ms on the rhythm strip
• conduction delay between the SA node and AV node

Question 11

Answer 11

2 AV Block Type I (The Wenchebach)

• PR Interval prgressively gets longer until there is a P wave but no QRS (called a drop beat)
• conduction delay between teh SA and AV node is getting worse since now were losing ventricular contraction

Question 12

Answer 12

The Notorious 3 AV Block

• wide and loppy QRS with P waves that are sporadically spaced throughout the rhythm, PR intervals are never the same.
• P waves are beating at their own rate, QRS are beating at their own rate, pacemaker cells refuse to talk to eachother.

Question 13

Answer 13

Left Bundle Branch Block (LBBB)

• wide QRS in the V1 on the 12-Lead EKG
• in determining the LBBB, imagine standing on the J point of the EKG looking back toward P wave, if the deflection you see is to your left (i.e. down) then it is a LBBB
• clinical scenario of crushing sub sternal chest pain radiating to the left arm, diaphoresis, nausea, and dyspnea, (MI)

Question 14

Answer 14

Right Bundle Branch Block (RBBB)

• characteristic “bunny ear” appearance in V1, typically present as a wide QRS
• Imagine standing on J point and looking down, if the deflection is to your right (i.e. up) then itis RBBB)
• Clincal presentaion can be indicative of pulmonary hypertension but generally more benign than LBBB.

Question 15

Answer 15

Hyperkalemia

• peaked T waves, morphology of the rhythm strips looks very unusual and wide.

(there is LBBB in this ECG as well)

Question 16

Answer 16

Hypokalemia

• characteristic U wave after the T wave

Question 17

Answer 17

Left Ventricle Hypertrophy (LVH)

• Extremely tall QRS, ST depression, and clinical signs of congestive heart faliure (CHF)
• caused by chronic HTN or aortic stenosis

Question 18

Answer 18

STEMI in Inferior (RCA)

• must have ST elevation in two or more contiguous leads, meaning two leads that are physically next to eachother and also correspond with the sme region within the heart.

Question 19

Answer 19

STEMI in Septal (LAD)

• must have ST elevation in two or more contiguous leads, meaning two leads that are physically next to eachother and also correspond with the sme region within the heart.

Question 20

Answer 20

Diffuse Subendocardial Ischemia

• prominent ST depression in leads I, II, aVL, aVF, V2-V6, with ST elecation in aVR, a prolonged PR interval
• possiblility of severe multivessel or left main coronary artery disease

Question 21

Answer 21

Acute Antero-lateral MI

• ST Elevation in V2, V3, V4 = LAD
• ST Elecvation in I and aVL = Circumflex
• Add together, left coronary branch in trouble before split

Question 22

Answer 22

Acute Inferior MI

• ST elevation in same Vessel (RCA) seen in II, III and aVf

Question 23

Answer 23

Posterior MI

• Will se prominant R waves in V1
• Will see ST depression in I, V2, adn V3

Arnce says flip it to see the obvious “ST elevation”